Method and apparatus for measuring and controlling the amounts of colored light in the printing of photographic transparencies

ABSTRACT

An apparatus for making prints from colored photographic transparencies performs color measuring and printing either simultaneously or sequentially. In simultaneous operation, part of the light passing through the transparency is utilized to terminate the exposures to the printing light of each of the primary colors. Sequentially auxiliary sources of light of each of the primary colors are adjusted to the same combination and intensity as in a selected portion of the transparency having an arbitrary combination of these colors. The adjusted light is then used to terminate the exposures to the light of each of the primary colors. A semitransparent mirror upon a movable sensing head diverts part of the light passing through the transparencies to terminate the exposures or uses, therefor the light adjusted. A fiber optic samples the combination of colors in a selected portion of the transparency during sequential measuring and projects them upon the sensing head. The auxiliary sources are then adjusted to the same combination and intensity as the selected portion of the transparency and this light is projected upon the sensing head during the sequential printing process to terminate the exposures to each of the primary colors. The sensing head slides back and forth under the focusing lens carrier within which the auxiliary sources of light and an apertured reflector (through which the fiber optic extends) are conveniently mounted with a diaphragm in-between for adjusting the overall intensity of the light from the auxiliary sources.

United States Patent Inventor Siegfried Barbieri Brixen Bel Bowen, ItalyAppl. No. 798,621 Filed Feb. 12, I969 Patented Aug. 24, 1971 AssigneeDurst A.G.

Bozen, Italy Priority Oct. 9, 1968 Italy 2572 METHOD AND APPARATUS FORMEASURING AND CONTROLLING THE AMOUNTS OF COLORED LIGHT IN THE PRINTINGOF PHOTOGRAPHIC TRANSPARENCIES Primary ExaminerSamuel S. MatthewsAssistant Examiner- Richard A. Wintercom Attorney--Connolly & HutzABSTRACT: An apparatus for making prints from colored photographictransparencies performs color measuring and printing eithersimultaneously or sequentially. In simultaneous operation, part of thelight passing through the transparency is utilized to terminate theexposures to the printing light of each of the primary colors.Sequentially auxiliary sources of light of each of the primary colorsare adjusted to the same combination and intensity as in a selectedportion of the transparency having an arbitrary combination of thesecolors. The adjusted light is then used to terminate the exposures tothe light of each of the primary colors. A semitransparent mirror upon amovable sensing head diverts part of the light passing through thetransparencies to terminate the exposures or uses, therefor the lightadjusted. A fiber optic samples the combination of colors in a selectedportion of the transparency during sequential measuring and projectsthem upon the sensing head. The auxiliary sources are then adjusted tothe same combination and intensity as the selected portion of thetransparency and this light is projected upon the sensing head duringthe sequential printing process to terminate the exposures to each ofthe primary colors. The sensing head slides back and forth under thefocusing lens carrier within which the auxiliary sources of light and anapertured reflector (through which the fiber optic extends) areconveniently mounted with a diaphragm in-between for adjusting theoverall intensity of the light from the auxiliary sources.

PATENTEU 1024mm 3,501,4 5 sum 2 or 2 Memo!) AND APPARATUS FoR-MEAsURrNoND CONTROLLING THE AMOUNTS or COLORED Lrcrrr rN THE PRINTING OFPHOTOGRAPHIC TRANSPARENCIES BACKGROUND OF THE INVENTION This inventionrelates to the automatic printing of colored photographictransparencies. Processes for making colored prints are known whichcompensate for color deficiencies in transparencies resulting fromvarious reasons (including: incorrect illumination during exposure ofthe film, variations in the composition of the processing baths,variations in temperature, and variations in the positive and negativeemulmary colors in theprinting light is measured during exposure of thetransparency and the exposures to each of the primary colors isterminated as soon as apredetermined amount of its 3 light has impingeduponthe photosensitive printing material.

- Such a process .is described in U.S. Pat. No. 3,127,267.

Another type of process now being utilized is the sequential measuringand printing process in which the relative color relationship in aselected portion of the transparency having an arbitrary colorcomposition is measured to govern the subsequent exposure of theprinting material. Whereas,'the simultaneous measuring and printingprocess is best adapted for rapid economical color .printing andenlarging of a wide .variety of subjects. The sequential process isbetter adapted for making high-grade studio and industrial'prints oftransparencies having a representative portion. where color compositioncanbe determined. Such representative portions are, for example, the face'of a person or the surface of a small grey card which can bephotographed simultaneously with the subject. Their colorcomposition ismeasured to determine the exposure conditions for the entiretransparency. An object of this invention is therefore to provide amethod and apparatus which may be alternatively v used in thesimultaneous or sequential color. measuring and printing of coloredphotographic transparencies. Another object is to provide a method for;utilizing a color printing apparatus, having means for individuallyterminating the exposures to the printing light of eachfof the primarycolors when predetermined quantitiesthereof have passed throughthetransparency for performing a sequential as well as a simultaneoustype of printing process.

. SUMMARY OF THE INVENTION Inaccordance with this inventionphotosensitive elements for the three primary. colors are mounted in asensing head' which actuates the control for terminating the exposuresto each of the primary colors. This sensing, head is movably mounted foralternative actuation by a portion. of the light passingthrough thetransparency for simultaneous measuring and printingor by exposure toauxiliary color light sources whose composition and overall intensityare coordinated with that in a selected portion of the transparencyhaving an arbit'rarycolor composition which has been preliminarilymeasured. A simultaneous. measuring and printing apparatus is easilyadapted for the sequential process by employing a movable sensing headhaving a semitransparent divertor which is inserted into the path of theexposure light for the simultaneous process and into the path of lightfrom adjusted auxiliary light sources during thesequential process. Thecolor composition of the selected portion of the transparency isconjected image in that a-much greaterlight intensity is available atthe transparency, whichis affected by the enlargement due to projection.Furthermore, there isconvenient access to the transparency for samplingin contrast-to the projected image which may be remote and difficult toreach, particularly-in all projections.

BRIEF DESCRIPTION OF THEDRAWING Novel features and advantages of thepresent invention will become apparent to one skilled in theart fromareading ofthe following description in conjunction with theaccompanying DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1. isshown the projecting head of enlarging and printing device '32 (notcompletely illustrated). Projecting head 30 includes lamphousing 1incorporating printing lamp .2, reflector 3, subtractive color filters4, 5 and6, opal disc 7,

deflecting mirror-8, condenser lenses 9 and 10 and transparency holder11 with transparency 12 inserted therein.

Color filters 4, 5 and 6 are moved in and out of the path=of theexposure light by actuating devices 34, and 36 which are, for example,of the type described in U.S. Pat. No. 3,41 1,847.

Focusing lens 13 is mounted upon the bottom of carrier 14 having chamber38 within it, later described in detail. Sensing head 15 is movablymounted to slide backand forth under lens carrier 14 over plate 23.semitransparent mirror 16 is veniently sampled by a flexiblelight-conducting fiber which abstracts the light and conducts it to thephotosensitive elements in the sensing head. This is better thanscanning the promounted at one end of sensing head 15andphotosensitiveelements or cells 40, 42 and 44 corresponding to thethree primary colorsare mounted within sensing head 15. Elements 40,42and 44 may be photoelectric cells, phototransistors or the like and theyare sensitized to respond only to specific ranges of the spectrum by theuse of filters in the additive primary colors orother means. Each cell40, 42 and 44is connected to a typical vphototube relay control circuitrepresented by block 46 for actuating solenoids (not specifically shown)in filter-actuating devices 34, 35 and-36 to' interposecorrespondingsubtractive colorfilters in the path of the printing lightas soon as each cell has. been exposed to a predetermined quantity ofits color component. Rectangle or block 46 represents'for example anassembly of typically phototube relay circuits-which may be for exampleof the type described ina publication entitled Phototubes" by RadioCorporation of America, Form PT- 20R1, 3-48 Copyright 1940, page 14 FIG.12. Any suitable solenoid-operating relay may be utilized within controlcomponent-46 to operate the solenoids in filter-actuating devices 34,35and 36. Subtractive color filters 4, 5 and 6, are, for example, of thetype described in U.S. Pat. No. 3,41 1,847.

Meters 48; 50 and 52 are insertedin electrical leads 54, 56

and 58 connecting photosensitive elements 40, 42 and 44 to controlcomponent 46. Meters 48,50 and '52 are, for example, of the ammeter typeand indicate the intensity of light sensed by photosensitive elements40, 42 and 44, which is utilized in a exposure process is begun,subtractive color filters 4, 5 and 6 arev retracted out of the path ofthe exposure light by solenoid devices 34, 35 and 36. Copying orprinting lamp 2 is then switched on. The light beams that it emitsarereflected and concentrated by reflector 3 throughcurved opal disc 7which diffuses it. The light beams are then reflected downwardly byreflecting mirror 8 and further concentrated by condensing lenses 9 and10. These light beams illuminate the original transparency l2 and passthrough focusing lens 13 to impinge, in the most part, uponphotosensitive-printing material 60. A small part of the light passingthrough the transparency and focusing lens 13 is deflected bysemitransparent mirror 16 into sensing head 15 and upon itsphotosensitive cells 40, 42 and 44. The quantities of light sensed bythe cells act through control component 46 and filter-actuating devices34, 35 and 36 to terminate the exposures of the corresponding color whena predetermined amount of its light has impinged upon correspondingphotosensitive cells 40, 42 and 44. The sensitivity of cells 40, 42 and44 is, of course, coordinated with that of particular printing material60 being used.

In FIG. 2 is shown apparatus 32 arranged for sequential measuring andexposing. In this position sensinghead is moved tothe right withsemitransparent mirror 16 out of the path of the rays of light passingthrough transparency 12 and focusing lens 13. Semitransparent mirror 16thus receives light through aperture'62 instead of focusing lens 13. Thelight through aperture 62 is from two alternative sources. One of themis auxiliary sources 18, 19 and 20 of light of the primary colors (blue,green and red). Their lights pass throughopal disc 21 (which diffusesit) upon auxiliary light-channeling device 22. Device 22 consists of anapertured mirror which directs light downwardly through aperture 62 ontosemitransparent mirror 16. Base plate 23 is opaque and prevents thislight from passing downwardly to protect photosensitive sheet 60 fromexposure thereby.

During the preliminary light-measuring step, the color content of aselected portion 64 of transparency l2 issampled and abstracted throughlight-conducting fiber or fiber optic 24 by positioning the head 25 offiber 24 under selected portion 64 of transparency 12. Selected portion64 has a color content which is representative of that in overalltransparency. Adjustment of fiber head 25 is accomplished by rod 26,which is for example made of a transparent material such as an acrylicplastic, through universally rotating and sliding coupling 66.

- Head 25 of fiber optic 24 is easily adjusted to the selectedportion ofthe transparency by determining the projected image at which head end 25is sharply projected while the remainder of fiber optic 24 retreatsbackwardly progressively out of focus. The lower end 68 of fiber optic24 is inserted through aperture of reflector 22 to permit its light tobe alternatively directed upon sensing head15 through semitransparentmirror 16. The intensity of the light of each of the three primarycolors is determined on meters 48, 50 and 52 for coordinating theintensities of auxiliary sources of light 18, 19 and 20 with suchintensities as later described.

Sources 18, 19 and 20 of the three primary colors (blue, green and red)are suitably colored lamps. They are connected to intensity controls 70,72 and 74 with which control knobs 76, 78 and 80 are associated. Tocoordinate them with the exposure light, printing lamp 2 is switched offand knobs 76, 78 and 80 are adjusted to provide the same intensitiespreviously obtained upon meters 40, 48 and 52.

A second adjustment of the overall intensities of lamps 18,

19 and 20 must be accomplished to make it similar to that of theexposure light. Measuring sensing head 15 is accordingly movedinto theleft-hand position (shown in FIG. 1) and the current from one of thephotosensitive cells 40, 42 or 44, such as-red-sensitive cell 44, isthen determined. Sensing head 15 is then moved back into the right-handposition (shown in FIG. 2) and diaphragm 27 is adjusted toprovide thepreviously measured photoelectric current in meter 52'connected toredsensitive cell 44. Y

During the final printing step, fiber optic 24is retracted out of theexposure light as shown in its-broken line position in FIG. 2. Exposurelamp is-switched on and the printing paper 60 (also shown in broken lineis exposed in the manner previously described to the full effect of theprinting light. Sensing head 15 is now exposed to the light fromauxiliary light sources 18, 19 and 20 which have been adjusted tocoordinate them with the relative amounts of light in the selectedportions of the transparency and also with the overall intensity of theprinting light. Mirror 22 reflects the light of the auxiliary sourcesthrough Semitransparent mirror 16 onto photosensitive cells 40, 42 and44, which actuate the interposition of subl. A method of sequentiallyoperating an apparatus for printing colored transparencies havinglight-responsive and control means for individually terminating theexposures to the printing light of each of the primary colors whenpredetermined quantities thereof have passed through saidtransparencies, said method comprising the steps of selecting a portionof said transparencies having an arbitrary combination of said primarycolors, adjusting auxiliary sources of light of said primary colors tothe same combination as in said selected portion, and utilizing saidadjusted auxiliary sources of light of said primary colors to actuatesaid light-responsive and con- .trol means to individually terminatesaid exposures to said light of said primary colors wherebysaid'transparencies are sequentially measured and printed.

2. A method as set forth in claim 1 wherein the intensity of each ofsaid auxiliary sources of light of said primary colors is separatelyadjusted in accordance with its content in i said selected portion.

3; A method as set forth in claim 2 wherein the overall intensity ofsaid auxiliary sources of light of said primary colors is adjustedsubstantially in accordance with the overall intensity of said printinglight transmitted through each of said transparencies.

4. A method as set forth in claim 3 wherein said overall intensity issubstantially adjusted in accordance with the light of I oneof saidprimary colors issuing from said auxiliary sources. 5. A method as setforth in claim 3 wherein said overall intensity is adjusted by adjustingadiaphragm disposed in the paths of light from said auxiliary sources. j

6. An apparatus for simultaneously and sequentially mea- I suring andprinting colored transparencies comprising exposure means for projectingprinting light of the primary colors through said transparencies,light-responsive and control means for terminating the exposures to thelight of each of said primary colors when predetermined quantitiesthereof have passed through said transparencies, analyzing means formeasuring the relative intensities of the light of each of said threeprimary colors in a selected portion of said transparency, auxiliarysources of said light of each of said primary colors, varying meansconnected to said auxiliary sources for adjusting the relativeintensities of said'light of each of said primary colors in accordancewith said relative intensities. detennined by said analyzing means, andlight-channeling means for directing either a portion of said printinglight passing through said transparencies or the adjusted light fromsaid auxiliary sources upon said light-responsive and control meanswhereby simultaneous or sequential measuring andv printing arealternatively accomplished.

7. An apparatus as set forth in claim 6 wherein said analyzing meansincludes sampling means for abstracting and pro jecting the light fromsaid selected portion of said trans parency.

8. An apparatus as set forth in claim 6 wherein said analyzing meansincludes light-evaluating means for comparing said light of each of saidprimary colors derived from said selected portion of said transparencieswith that from said auxiliary sources whereby said adjustment of saidlight of said primary colors from said auxiliary sources is guided. v

9. An apparatus as set forth inclaim 6 wherein said lightresponsive andcontrol means and said analyzing means include light-measuring means foreach of said primary colors.

10. An apparatus as set forth in claim 6 wherein said movablemeansconnects said light-channeling means to said apparatus foralternatively interposing said light-channeling means in said lightpassing through said transparencies for simultaneously measuring andprinting and for disposing said light-channeling means in the path oflight from said auxiliary sources during sequential printing aftermeasuring.

. 11. An apparatus as set forth in claim 10 wherein said lightchannelingmeans comprises a semitransparent mirror.

12. An apparatus as set forth in claim 11 wherein said movable meanscomprises slide means.

13. An apparatus as set forth in claim 10 wherein said lightresponsiveand control means includes photosensitive means, said semitransparentreflector and said photosensitive means being mounted upon a sensinghead, and slide means connects said sensing head to said apparatus.

l4. An apparatus as set forth in claim 13 wherein said apparatusincludes a focusing lens, said focusing lens being mounted upon acarrier, said analyzing means including sampling means for abstractingand projecting said selected portion of said light, said sampling meansalso being mounted upon said carrier, and said slide means beingconstructed and arranged to permit said semitransparent reflector to bealternatively disposed in the path of light from said focusing lens orsaid sampling means.

15. An apparatus as set forth in claim 14 wherein said auxiliary sourcesof light are mounted upon said carrier, and auxiliary light-channelingmeans is mounted on said carrier for directing light'from said samplingmeans and said auxiliary sources of light upon said semitransparentreflector.

16. An apparatus as set forth in claim 15 wherein said carri- 17. Anapparatus as set forth in claim 16 wherein said auxiliarylight-channeling means comprises an apertured mirror,

said sampling and abstracting means comprise light-conduct ing fiber,and one end of said light-conducting fiber passing through saidapertured reflector.

18. An apparatus as set forth in claim 17 wherein said ap paratusincludes a transparency holder, and adjustable support means movablymounts the other end of said light-conducting fiber adjacent saidtransparency holder for projecting light from said selected portion ofsaid transparency to said auxiliary light-channeling means.

19. An apparatus as set forth in claim 17 wherein said ad justablediaphragm means is mounted in said chamber between said auxiliarysources of light and auxiliary lightchanneling means, whereby theoverall intensity of the light from said auxiliary sources of light isadjusted.

20. An apparatus as set forth in claim 18 wherein said semitransparentreflector is mounted at one end of said sensing head, and saidphotosensitive means is mounted within said sensing head.

1. A method of sequentially operating an apparatus for printing coloredtransparencies having light-responsive and control means forindividually terminating the exposures to the printing light of each ofthe primary colors when predetermined quantities thereof have passedthrough said transparencies, said method comprising the steps ofselecting a portion of said transparencies having an arbitrarycombination of said primary Colors, adjusting auxiliary sources of lightof said primary colors to the same combination as in said selectedportion, and utilizing said adjusted auxiliary sources of light of saidprimary colors to actuate said light-responsive and control means toindividually terminate said exposures to said light of said primarycolors whereby said transparencies are sequentially measured andprinted.
 2. A method as set forth in claim 1 wherein the intensity ofeach of said auxiliary sources of light of said primary colors isseparately adjusted in accordance with its content in said selectedportion.
 3. A method as set forth in claim 2 wherein the overallintensity of said auxiliary sources of light of said primary colors isadjusted substantially in accordance with the overall intensity of saidprinting light transmitted through each of said transparencies.
 4. Amethod as set forth in claim 3 wherein said overall intensity issubstantially adjusted in accordance with the light of one of saidprimary colors issuing from said auxiliary sources.
 5. A method as setforth in claim 3 wherein said overall intensity is adjusted by adjustinga diaphragm disposed in the paths of light from said auxiliary sources.6. An apparatus for simultaneously and sequentially measuring andprinting colored transparencies comprising exposure means for projectingprinting light of the primary colors through said transparencies,light-responsive and control means for terminating the exposures to thelight of each of said primary colors when predetermined quantitiesthereof have passed through said transparencies, analyzing means formeasuring the relative intensities of the light of each of said threeprimary colors in a selected portion of said transparency, auxiliarysources of said light of each of said primary colors, varying meansconnected to said auxiliary sources for adjusting the relativeintensities of said light of each of said primary colors in accordancewith said relative intensities determined by said analyzing means, andlight-channeling means for directing either a portion of said printinglight passing through said transparencies or the adjusted light fromsaid auxiliary sources upon said light-responsive and control meanswhereby simultaneous or sequential measuring and printing arealternatively accomplished.
 7. An apparatus as set forth in claim 6wherein said analyzing means includes sampling means for abstracting andprojecting the light from said selected portion of said transparency. 8.An apparatus as set forth in claim 6 wherein said analyzing meansincludes light-evaluating means for comparing said light of each of saidprimary colors derived from said selected portion of said transparencieswith that from said auxiliary sources whereby said adjustment of saidlight of said primary colors from said auxiliary sources is guided. 9.An apparatus as set forth in claim 6 wherein said light-responsive andcontrol means and said analyzing means include light-measuring means foreach of said primary colors.
 10. An apparatus as set forth in claim 6wherein said movable means connects said light-channeling means to saidapparatus for alternatively interposing said light-channeling means insaid light passing through said transparencies for simultaneouslymeasuring and printing and for disposing said light-channeling means inthe path of light from said auxiliary sources during sequential printingafter measuring.
 11. An apparatus as set forth in claim 10 wherein saidlight-channeling means comprises a semitransparent mirror.
 12. Anapparatus as set forth in claim 11 wherein said movable means comprisesslide means.
 13. An apparatus as set forth in claim 10 wherein saidlight-responsive and control means includes photosensitive means, saidsemitransparent reflector and said photosensitive means being mountedupon a sensing head, and slide means connects said sensing head to saidapparatus.
 14. An apparatus as set forth in claim 13 wherein saidapparatus incluDes a focusing lens, said focusing lens being mountedupon a carrier, said analyzing means including sampling means forabstracting and projecting said selected portion of said light, saidsampling means also being mounted upon said carrier, and said slidemeans being constructed and arranged to permit said semitransparentreflector to be alternatively disposed in the path of light from saidfocusing lens or said sampling means.
 15. An apparatus as set forth inclaim 14 wherein said auxiliary sources of light are mounted upon saidcarrier, and auxiliary light-channeling means is mounted on said carrierfor directing light from said sampling means and said auxiliary sourcesof light upon said semitransparent reflector.
 16. An apparatus as setforth in claim 15 wherein said carrier includes a chamber, saidauxiliary sources of light being mounted at one end of said chamber, aportion of said sampling means and said auxiliary light-channeling meansbeing mounted at another end of said chamber, said focusing lens beingmounted at an intermediate portion of said chamber, and a pair ofapertures in said chamber associated with said focusing lens and saidauxiliary light-channeling means where through light is alternativelydirected to said semitransparent reflector.
 17. An apparatus as setforth in claim 16 wherein said auxiliary light-channeling meanscomprises an apertured mirror, said sampling and abstracting meanscomprise light-conducting fiber, and one end of said light-conductingfiber passing through said apertured reflector.
 18. An apparatus as setforth in claim 17 wherein said apparatus includes a transparency holder,and adjustable support means movably mounts the other end of saidlight-conducting fiber adjacent said transparency holder for projectinglight from said selected portion of said transparency to said auxiliarylight-channeling means.
 19. An apparatus as set forth in claim 17wherein said adjustable diaphragm means is mounted in said chamberbetween said auxiliary sources of light and auxiliary light-channelingmeans whereby the overall intensity of the light from said auxiliarysources of light is adjusted.
 20. An apparatus as set forth in claim 18wherein said semitransparent reflector is mounted at one end of saidsensing head, and said photosensitive means is mounted within saidsensing head.